Sewing Machine

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Transcript of Sewing Machine

Sewing Machine is a machine used to stitch fabric and other materials together with thread. Sewing machines were invented during the first Industrial Revolution to decrease the amount of manual sewing work performed in clothing companies. Since the invention of the first working sewing machine, generally considered to have been the work of Englishman Thomas Saint in 1790,[1] the sewing machine has greatly improved the efficiency and productivity of the clothing industry.Home sewing machines are designed for one person to sew individual items while using a single stitch type. In a modern sewing machine the fabric easily glides in and out of the machine without the inconvenience of needles and thimbles and other such tools used in hand sewing, automating the process of stitching and saving time.Industrial sewing machines, by contrast, are larger, faster, more complex, and more varied in their size, cost, appearance, and task.The fabric shifting mechanism may be a workguide or may be pattern-controlled (e.g., jacquard type). Some machines can create embroidery-type stitches. Some have a work holder frame. Some have a workfeeder that can move along a curved path, while others have a workfeeder with a work clamp. Needle guards, safety devices to prevent accidental needle-stick injuries, are often found on modern sewing machines.

HistoryCharles Fredrick Wiesenthal, a German-born engineer working in England was awarded the first British patent for a mechanical device to aid the art of sewing, in 1755. His invention consisted of a double pointed needle with an eye at one end.[2]The "Sewing Hand“, invented by Josef Madersperger in the early 19th century, (displayed at the Technisches Museum Wien).]] In 1790, the English inventor Thomas Saint invented the first sewing machine design, but he did not successfully advertise or market his invention.[3] His machine was meant to be used on leather and canvas material. It is likely that Saint had a working model but there is no evidence of one; he was a skilled cabinet maker and his device included many practically functional features: an overhanging arm, a feed mechanism (adequate for short lengths of leather), a vertical needle bar, and a looper.His sewing machine used the chain stitch method, in which the machine uses a single thread to make simple stitches in the fabric. A stitching awl would pierce the material and a forked point rod would carry the thread through the hole where it would be hooked underneath and moved to the next stitching place, where the cycle would be repeated, locking the stitch.[4] Saint’s machine was designed to aid the manufacture of various leather goods, including saddles and bridles, but it was also capable of working with canvas, and was used for sewing ship sails. Although his machine was very advanced for the era, the concept would need steady improvement over the coming decades before it could become a practical proposition. (In 1874 a sewing machine manufacturer, William Newton Wilson, found Saint's drawings in the London Patent Office, made adjustments to the looper, and built a working machine, currently owned by the London Science Museum.)

Types of sewing machineElectric sewing machines

Manual sewing machines Generally limited to some old heritage models, manual sewing machines are operated by turning a hand wheel as you guide the fabric under the needle with the other hand.The only place you’re likely to come across one of these is an antique shop, museum, a schoolroom or perhaps hidden away in the loft.

Besides the basic motion of needles, loopers and bobbins, the material being sewn must move so that each cycle of needle motion involves a different part of the material. This motion is known as feed, and sewing machines have almost as many ways of feeding material as they do of forming stitches. For general categories, there are: drop feed, needle feed, walking foot, puller, and manual. Often, multiple types of feed are used on the same machine.Puller feedSome factory machines and a few household machines are set up with an auxiliary puller feed, which grips the material being sewn (usually from behind the needles) and pulls it with a force and reliability usually not possible with other types of feed. Puller feeds are seldom built directly into the basic sewing machine.Basic Parts of a Sewing Machine and Their Functions

1. Spool pin: It is fitted on top of the arm to hold the reel. 2. Thread guide: It holds the thread in position from the spool to the needle. 3. Tension disc: The two concave discs put together with the convex sides facing each other. The thread passes between the two. The tension of the thread is adjusted by a spring and nut which increases or decreases pressure 4. Take up lever: It is a lever fitted to the body of the arm. Its up and down motion feeds the thread to the needle and tightens the loop formed by the shuttle. 5. Needle bar: This is a steel rod to hold the needle at one end with the help of a clamp. Its main function is to give motion to the needle. 6. Bobbin case: This moves into position to catch the top thread and form the stitch as the needle is lowered into the bobbin chamber. 7. Presser foot: It is fixed to the presser bar to hold the cloth firmly in position when lowered. 8. Presser foot lifter: A lever attached to the presser bar for raising and lowering the presser foot. 9. Stitch regulator: This controls the length of the stitch. 10. Bobbin winder: A simple mechanism used for winding thread on the bobbin. 11. Fly Wheel: When this is made to revolve, it works the mechanism of the motion 12. Clutch or Thumb Screw: This is in the center of the fly wheel and it engages and disengages the stitching mechanism. 13. Slide Plate: A rectangular plate, which facilitates the removal of the bobbin case without lifting the machine. 14. Needle Plate or Throat Plate: A semi-circular disc with a hole to allow the needle to pass through it. 15. Feed dog: This consists of a set of teeth fitted below the needle plate. It helps to move the cloth forward while sewing. 16. Face plate: A cover which on removal gives access to the oiling points on the needle bar, presser bar and take-up lever. 17. Spool pin for bobbin winding: Spool of thread is placed on this at the time of bobbin winding.

Sewing Machineand its Parts9-SilverMembers:Erika P. Aquino Bridget Miles P. Cuya Joanne EspenidaA basic electric sewing machine contains a motor in the body which drives the needle in the top part of the sewing machine and controls a bobbin and feed dogs in the lower part under the needle plate. See Jargon buster for more detail on the parts of a sewing machine.These models allow for a reasonable range and size of stitches, which are selected by turning a dial. They are much faster and more accurate than old-fashioned manual models.Computerised sewing machinesThese do everything that ordinary electric machines do, plus an awful lot more. These sewing machines are controlled by computer chips with the correct tension, length and width programmed in by the manufacturer for each stitch style.They are operated using a touchpad and computer screen, and you can download programs from your PC. The machine can memorise past work and will also store hundreds of different stitches for you to choose from.

Overlocker machinesOverlocker machines are used to stop fraying and give a professional finish to the seams of a garment.Their main purpose is to neaten seams which they achieve by trimming while sewing.An overlocker sews faster than a sewing machine and there are attachments available that enable it to be particularly useful for stitching rolled hems, gathering and attaching bindings.

Stitch formationSewing machines can make a great variety of plain or patterned stitches. Ignoring strictly decorative aspects, over three dozen distinct stitch formations are formally recognized by the ISO 4915:1991 standard, involving one to seven separate threads to form the stitch.Plain stitches fall into four general categories: lockstitch, chainstitch, overlock, and coverstitch.Lockstitch is the familiar stitch performed by most household sewing machines and most industrial "single needle" sewing machines from two threads, one passed through a needle and one coming from a bobbin or shuttle. Each thread stays on the same side of the material being sewn, interlacing with the other thread at each needle hole by means of a bobbin driver.LockstitchChainstitch was used by early sewing machines and has two major drawbacks:1. The stitch is not self-locking, and if the thread breaks at any point or is not tied at both ends, the whole length of stitching comes out. It is also easily ripped out.2. The direction of sewing cannot be changed much from one stitch to the next, or the stitching process fails.A better stitch was found in the lockstitch. The chainstitch is still used today in clothing manufacture, though due to its major drawback it is generally paired with an overlock stitch along the same seam.

ChainstitchZigzag stitchA zigzag stitch is variant geometry of the lockstitch. It is a back-and-forth stitch used where a straight stitch will not suffice, such as in preventing raveling of a fabric, in stitching stretchable fabrics, and in temporarily joining two work pieces edge-to-edge.CoverstitchCoverstitch is formed by two or more needles and one or two loopers. Like lockstitch and chainstitch, coverstitch can be formed anywhere on the material being sewn. One looper manipulates a thread below the material being sewn, forming a bottom cover stitch against the needle threads. Feed mechanismsDrop feedThe drop feed mechanism is used by almost all household machines and involves a mechanism below the sewing surface of the machine. When the needle is withdrawn from the material being sewn, a set of "feed dogs" is pushed up through slots in the machine surface, then dragged horizontally past the needle. The dogs are serrated to grip the material, and a "presser foot" is used to keep the material in contact with the dogs. At the end of their horizontal motion, the dogs are lowered again and returned to their original position while the needle makes its next pass through the material. While the needle is in the material, there is no feed action. Almost all household machines and the majority of industrial machines use drop feed.aNeedle feedA needle feed, used only in industrial machines, moves the material while the needle is in the material. In fact, the needle may be the primary feeding force. Some implementations of needle feed rock the axis of needle motion back and forth, while other implementations keep the axis vertical while moving it forward and back. In both cases, there is no feed action while the needle is out of the material. Needle feed is often used in conjunction with a modified drop feed, and is very common on industrial two needle machines.Walking footA walking foot replaces the stationary presser foot with one that moves along with whatever other feed mechanisms the machine already has. As the walking foot moves, it shifts the workpiece along with it.Manual feedA manual feed is used primarily in freehand embroidery, quilting, and shoe repair. With manual feed, the stitch length and direction is controlled entirely by the motion of the material being sewn. Frequently some form of hoop or stabilizing material is used with fabric to keep the material under proper tension and aid in moving it around. Most household machines can be set for manual feed by disengaging the drop feed dogs. Most industrial machines can not be used for manual feed without actually removing the feed dogs.